1. Field of the Invention
The present invention relates to means for attaching plate building elements to a base and particularly concerns such an attachment means for attaching plate building elements of glass ceramic having a small coefficient of thermal expansion.
2. Description of the Prior Art
When decorative sheet or plate building elements composed of glass, glass-ceramic or similar material having a coefficient of thermal expansion less than 50 .times. 10.sup..sup.-7 /.degree.C are attached to a metallic base, typically steel, the building element is subjected to repeated stresses and strains as the ambient temperature changes. Normal attachment means such as bolts placed through holes in the sheet building element and secured to the base cause undesirable mechanical stress by the relatively greater thermal expansion of the base leading to frequent fracturing of the plate building element.
Another attachment means which has been used includes a rim of metal cushioned with rubber or asbestos extending over onto the front surface of the plate. The rim protects the edge of the plate but represents an esthetically unpleasing appearance and a source of dirt that is difficult to remove. Furthermore, the use of such rims makes it impossible to provide a flat surface comprising of a plurality of the construction plates.
It is, therefore, an object of the present invention to provide a means for attaching plate elements which have a coefficient of thermal expansion of less than 50 .times. 10.sup..sup.-7 .degree.C which can safely and easily attach the plate element to a base having a coefficient of thermal expansion greater than that of the plate element while minimizing the mechanical stresses transferred to the plate element by the difference in coefficients of thermal expansion.
A further object of the invention is to provide a means for attaching plate elements of the type which have no rim extending above the front surface of the plate element thereby permitting the simultaneous arrangement of a plurality of the plates into a large plane surface having no discontinuities.